Schizophrenia is one of the most debilitating and costly mental illnesses in the United States, with peak incidence in individuals aged 14-25 and causing annual direct and indirect costs of over $62.7 billion (Wu et al., 2005). Several studies suggest that early identification and treatment can delay onset and decrease the severity of schizophrenia, leading to a significant reduction in the irreversible neuroanatomical changes and cognitive deficits often associated with the onset of schizophrenia (McGlashan et al, 2006; Piontkewitz, et al, 2009; Simon et al., 2007). The critical barrier to advances in prodromal and early psychosis (PEP) research and treatment has been the identification of PEP individuals who are at risk of conversion to a psychotic disorder. Clinician-administered PEP screening assessments are time-consuming and costly, both in terms of required expertise and administration time (Lindenmayer et al, 2007). The proposed project will facilitate PEP screening and clinical research recruitment with the development of brief paper and computerized self-report PEP assessments that are appropriate for public sector mental health outpatients, 14-25 years of age. To accomplish this, we will utilize state-of-the art self- report item development methodology that is novel to PEP research, namely cognitive interviewing (CI) with 50 PEP outpatients as well as item response theory (IRT) analysis of responses from 1000 outpatients with varying levels of severity, including no symptoms, PEP, and a psychotic disorder. These methods will reduce population-specific biases and increase measurement precision and thereby, predictive validity. We will establish the convergent and predictive validit of our assessments against the SIPS and 12-month SCID-based diagnostic outcomes, respectively, as well as the predictive validity of the PQ-92 against the same outcomes. Computerized versions of the new PEP screeners will permit rapid scoring, clinical and research report generation, and follow-up with a computerized structured diagnostic assessment, the NetSCID, when integrated into our existing secure diagnostic Web portal. We have partnered with highly skilled consultants including three NIMH North American Prodrome Longitudinal Study (NAPLS) PIs, two PIs from the NIMH Recovery After an Initial Schizophrenia Episode (RAISE) clinical trial, a researcher representing the foremost ultra-high risk (UHR) research center outside the U.S., and a quantitative expert in IRT. This project is likely to have a substantial impact on the identification and treatment of PEP. It will facilitate PEP research by increasing the predictive validity of self-report screening thereby improving clinical trial recruitment. Routine screening of outpatients with our instruments may enable a greater number of PEP individuals to gain access to NAPLS-validated interventions, which may delay or prevent onset of a psychotic disorder; thereby serving to improve the lives of people suffering from psychosis and their families; prominent components of NIMH's overall mission.